Introduce lithium-ion battery separator coating technology and methods

Lithium-ion battery separator coating technology methods and methods. In recent years, with the heating up of the power lithium-ion battery market, wet-coated diaphragms have become more and more popular in China. There is even a view in the industry that wet-coated diaphragms will dominate the future power lithium battery diaphragm market. Lithium-ion battery wet + coating has been recognized in the industry as the development direction of separators. Today, the author of Cuneng Electric has compiled relevant content about the coating slurry formula and coating process. Welcome everyone to read and leave a message for supplementary information. Lithium-ion battery separator coating technology methods require different coating technologies to be used according to downstream requirements for specific performance and the positioning of lithium-ion battery separator products. For coating, the core of the technology lies in the formulation of the slurry. At the same time, the cost of the slurry in the diaphragm coating is relatively large. Generally, the slurry accounts for 65% of the total coating cost. The development direction of power lithium-ion batteries is a high-output, high-capacity, and fast-charging mode. The technology and process requirements for diaphragm coating will also be more diversified. The continuous innovation of formula will also become the core competitiveness of coating. Diaphragm ceramic coating slurry mainly includes four important components: ceramic particles, binder, solvent and additives, and different slurry ratios are required for different application scenarios. The rigid support of ceramics makes the ceramic modified diaphragm have excellent thermal stability and dimensional integrity at high temperatures, and supports the maintenance of the diaphragm structure at high temperatures. The diaphragm matrix is u200bu200bclosed and transparent at high temperatures, and the diaphragm is not coated. The shrinkage is serious, and the coating lithium-ion battery separator has greatly improved shrinkage resistance due to the presence of the ceramic layer, and the mechanical properties and safety are better. Lithium ion battery separator Lithium ion battery thin film coating method, flexible and diverse membrane coatings are not technically difficult. Gravure roll coating, dip coating, narrow coating or spraying can be used. Domestic mainstream film manufacturers and a large number of It can be achieved by OEM. Gravure roll gravure roll coating process is a commonly used coating method at present. The micro gravure roll takes the slurry out of the paste box, scrapes off the excess coating with a thick blade, and then coats it on the diaphragm under pressure. The principle of the method is simple, the groove volume of the concave roller is easy to control, and the product accuracy is good. The disadvantage is that due to the high hardness of the alumina ceramic particles, the anilox roll is easy to wear, which will cause the coating to gradually become thinner during the continuous coating process, and a new roll must be replaced; when the target thickness of the coating changes, the roll must be replaced, which is not flexible Adjustment. Narrow slot extrusion coating Narrow slot extrusion coating, referred to as narrow slot extrusion coating, is the process of extruding the slurry from the nozzle onto the diaphragm under a certain pressure. The coating thickness is controlled by the nozzle slit width and the metering pump. This process is suitable for a wide range of viscosity, good product accuracy, thin layer coating and high coating speed, but it is difficult to maintain the extrusion nozzle. The basic principle of dip coating is to immerse the lithium ion battery membrane in a slurry of a certain concentration for a certain period of time, dry or take it out and dry to obtain a certain thickness of coating on the surface of the membrane. The principle and operation of this method are simple, but the thickness control is relatively difficult. Electrospinning Electrospinning is a process in which the slurry is sprayed onto the membrane by electric field force to charge the slurry. Under the application of electric field force, the slurry breaks through the surface tension and forms a jet of nanowires on the film. This process has a wide range of applicable materials, convenient operation, large specific surface area, high porosity, good fiber uniformity and high yield, but its shortcomings are low crystallinity, low orientation, poor mechanical properties and mechanical properties, and it needs heat treatment. Optimization, mixing and other modification methods. At present, lithium-ion battery diaphragm coating processing equipment basically needs to be imported, with stable supply and compact equipment. A production line requires an investment of 1.5-2 million yuan, with an annual output of about 4 million square meters. For companies that have both substrate production capacity and substrate processing capabilities, each substrate production line generally requires 10 coating production lines. Lithium-ion battery film coating manufacturers mostly use the gravure roller coating method. Statement: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: What is a lithium-ion battery cathode material?